Gaskets have been extensively used to separate two volumes containing different fluids at different pressures and temperatures, the parts delimiting these volumes being fixed with respect to one another. In certain turbo-propeller engines, this is the case with pressurization air circuits where the under-pressure hot air, taken from the engines and before it fulfills its function, circulates in confined spaces with difficult access. For these places, the operations for overhauling and maintenance can be extremely difficult to carry out owing to lack of space and/or difficulty for the operator to gain access. Moreover, because of these difficulties, this operator may, generally speaking, not be able to use a booster tool.
This type of joint ought to ensure a certain amount of imperviousness between two pipe elements with sealing to be effected with an extremely slight clamping. In addition, a variable crushing of the gasket may be obtained over several millimeters so that the approach, joining and locking of the pipe elements may be effected manually without having recourse to using special mechanical tools.
Moreover, it is essential to take account of the fact that crushing of the gasket may not be regular and change over a period of time when the device is being used. In fact, following differential thermal expansion of the pipes, variation of the joint on this perimeter may vary by several millimeters.
The French patent published under number 2 692 019 discloses a flexible joint with a jacket used on aircraft turbo-propeller engines. This gasket able to ensure static imperviousness between an internal medium and an external medium, and dynamic imperviousness between two portions of the internal medium.
It mainly comprises a central core in the form of a spring surrounded by three casings, the second of the latter being able to ensure dynamic imperviousness between the mobile and fixed elements. The external casing ensures static imperviousness between the two parts of the fixed elements.
The extremity of the jacket is slightly in contact with the mobile element and makes it possible for each medium to be in contact with the mobile element on both sides of the jacket.
By virtue of the flexible extremity of the jacket, this type of joint ensures dynamic imperviousness between one or several fixed parts and one or several static parts. It is not designed to be used to ensure static imperviousness in places with limited accessibility and where the mounting of a gasket proves to be a delicate operation.
The purpose of this invention is to resolve this drawback by offering a fully static gasket seal able to be mounted in places not accessible to a motor without having recourse to using special tools.